Abstract
1. Ten healthy subjects were randomised to inhale salbutamol via a standard metered-dose inhaler (MDI), or via a modified metered-dose actuator device (MA). Previously published radiolabelled aerosol data had shown that the MA device produced a lower aerosol velocity, reduced oropharyngeal deposition, but with unchanged pulmonary deposition. 2. Dose-response curves (DRC) were constructed with the following cumulative doses of salbutamol: 200 microg, 600 microg (200 microg + 400 microg), 1400 microg (600microg + 800 microg) ad 2600 microg (1400 + 1200 microg). Dose increments were made every 30 min and measurements of extrapulmonary beta2-adrenoceptor responses were performed 20 min after each dose. In addition, plasma salbutamol concentrations were also measured immediately before and for up to 60 min after the last dose. 3. Baseline values were not significantly different between the two study days for any of the measured parameters. 4. Cmax (ng ml(-1)) for plasma salbutamol (as means and 95% CI for difference between MA and MDI) was: 2.0 (0.3-3.7), P = 0.03. Values for t(max) (min), median and range: MA 5 (5-10) vs MDI 5 (5-10); and AUC 0-60, (ng ml(-1) min, mean and 95% CI for difference between MA and MDI): 69 (-5-143), were not significantly different between the two devices. 5. There was a significant (P < 0.01) left shift in the DRC with the MA device compared with the MDI, for hypokalaemic, finger tremor, chronotropic and electrocardiographic (Twave, Q-Tc) responses to salbutamol. Values for the hypokalaemic response (mmol l(-1)) at 2600 microg were (as change from baseline, means and 95% CI for difference between MA and MDI): 0.23 (0.10-0.36). 6. Thus, the MA device produced greater systemic absorption of salbutamol, and associated extrapulmonary beta2-adrenoceptor responses compared with a standard MDI. These results, therefore, suggest that data from radiolabelled aerosol deposition studies may not predict the systemic absorption of inhaled beta2-adrenoceptor agonists.
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Selected References
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- Brown P. H., Blundell G., Greening A. P., Crompton G. K. Do large volume spacer devices reduce the systemic effects of high dose inhaled corticosteroids? Thorax. 1990 Oct;45(10):736–739. doi: 10.1136/thx.45.10.736. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Collier J. G., Dobbs R. J., Williams I. Salbutamol aerosol causes a tachycardia due to the inhaled rather than the swallowed fraction. Br J Clin Pharmacol. 1980 Mar;9(3):273–274. doi: 10.1111/j.1365-2125.1980.tb04837.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cushley M. J., Lewis R. A., Tattersfield A. E. Comparison of three techniques of inhalation on the airway response to terbutaline. Thorax. 1983 Dec;38(12):908–913. doi: 10.1136/thx.38.12.908. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fuglsang G., Pedersen S. Comparison of Nebuhaler and nebulizer treatment of acute severe asthma in children. Eur J Respir Dis. 1986 Aug;69(2):109–113. [PubMed] [Google Scholar]
- Küng M., Croley S. W., Phillips B. A. Systemic cardiovascular and metabolic effects associated with the inhalation of an increased dose of albuterol. Influence of mouth rinsing and gargling. Chest. 1987 Mar;91(3):382–387. doi: 10.1378/chest.91.3.382. [DOI] [PubMed] [Google Scholar]
- Lindgren S. B., Larsson S. Inhalation of terbutaline sulphate through a conventional actuator or a pear-shaped tube: effects and side effects. Eur J Respir Dis. 1982 Nov;63(6):504–509. [PubMed] [Google Scholar]
- Lipworth B. J., Clark R. A., Dhillon D. P., McDevitt D. G. Subsensitivity of beta-adrenoceptor responses in asthmatic patients taking regular low dose inhaled salbutamol. Eur J Clin Pharmacol. 1990;38(2):203–205. doi: 10.1007/BF00265986. [DOI] [PubMed] [Google Scholar]
- Lipworth B. J., Clark R. A., Dhillon D. P., Moreland T. A., Struthers A. D., Clark G. A., McDevitt D. G. Pharmacokinetics, efficacy and adverse effects of sublingual salbutamol in patients with asthma. Eur J Clin Pharmacol. 1989;37(6):567–571. doi: 10.1007/BF00562546. [DOI] [PubMed] [Google Scholar]
- Lipworth B. J., McDevitt D. G. Beta-adrenoceptor responses to inhaled salbutamol in normal subjects. Eur J Clin Pharmacol. 1989;36(3):239–245. doi: 10.1007/BF00558154. [DOI] [PubMed] [Google Scholar]
- Lipworth B. J., McDevitt D. G., Struthers A. D. Systemic beta-adrenoceptor responses to salbutamol given by metered-dose inhaler alone and with pear shaped spacer attachment: comparison of electrocardiographic, hypokalaemic and haemodynamic effects. Br J Clin Pharmacol. 1989 Jun;27(6):837–842. doi: 10.1111/j.1365-2125.1989.tb03447.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lipworth B. J., Struthers A. D., McDevitt D. G. Tachyphylaxis to systemic but not to airway responses during prolonged therapy with high dose inhaled salbutamol in asthmatics. Am Rev Respir Dis. 1989 Sep;140(3):586–592. doi: 10.1164/ajrccm/140.3.586. [DOI] [PubMed] [Google Scholar]
- Morris J., Milledge J. S., Moszoro H., Higgins A. The efficacy of drug delivery by a pear-shaped spacer and metered dose inhaler. Br J Dis Chest. 1984 Oct;78(4):383–387. [PubMed] [Google Scholar]
- Newman S. P., Clarke S. W. Bronchodilator delivery from Gentlehaler, a new low-velocity pressurized aerosol inhaler. Chest. 1993 May;103(5):1442–1446. doi: 10.1378/chest.103.5.1442. [DOI] [PubMed] [Google Scholar]
- Newman S. P., Millar A. B., Lennard-Jones T. R., Morén F., Clarke S. W. Improvement of pressurised aerosol deposition with Nebuhaler spacer device. Thorax. 1984 Dec;39(12):935–941. doi: 10.1136/thx.39.12.935. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Newman S. P., Pavia D., Morén F., Sheahan N. F., Clarke S. W. Deposition of pressurised aerosols in the human respiratory tract. Thorax. 1981 Jan;36(1):52–55. doi: 10.1136/thx.36.1.52. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Prahl P., Jensen T. Decreased adreno-cortical suppression utilizing the Nebuhaler for inhalation of steroid aerosols. Clin Allergy. 1987 Sep;17(5):393–398. doi: 10.1111/j.1365-2222.1987.tb02031.x. [DOI] [PubMed] [Google Scholar]
- Rahman A. R., McDevitt D. G., Struthers A. D., Lipworth B. J. Sex differences in hypokalaemic and electrocardiographic effects of inhaled terbutaline. Thorax. 1992 Dec;47(12):1056–1059. doi: 10.1136/thx.47.12.1056. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Selroos O., Halme M. Effect of a volumatic spacer and mouth rinsing on systemic absorption of inhaled corticosteroids from a metered dose inhaler and dry powder inhaler. Thorax. 1991 Dec;46(12):891–894. doi: 10.1136/thx.46.12.891. [DOI] [PMC free article] [PubMed] [Google Scholar]